System and method for phase motion detection for YC separation

A motion detection system adapted to detect motion in a current frame of a composite video signal, the motion detection system comprising:

• a luminance motion detector adapted to generate a luminance motion signal using the current frame and a previous frame of the composite video signal;
• a phase motion detector adapted to generate a phase motion signal using the current frame and a plurality of previous frames of the composite video signal;
• a demodulated phase motion detector adapted to generate a demodulated phase motion signal using the current frame and the plurality of previous frames of the composite video signal;
• a selector adapted to select a maximum motion signal among the luminance motion signal, the phase motion signal, and the demodulated phase motion signal;
• a saturation circuit adapted to clip the maximum motion signal;
• and
• a circuit adapted to process the clipped maximum motion signal in a multi-pixel horizontal window to generate a final motion signal.

A luminance and chroma separation circuit adapted to separate a current frame of a composite video signal into a luminance signal and a chroma signal, the luminance and chroma separation circuit comprising:

• an inter-line correlator adapted to generate a relative chroma correlation value using a plurality of lines of the current frame;
• a line comb adapted to generate a weighted sum of inter-line pixel differences of the current frame using the relative chroma correlation value;
• a frame comb adapted to subtract a previous frame of the composite video signal from the current frame;
• a motion detector adapted to detect motion in the current frame and generate a corresponding detected motion signal;
• a mixer circuit adapted to combine the weighted sum of inter-line pixel differences, an output of the frame comb, and the detected motion signal to generate the chroma signal;
• and
• a subtractor adapted to subtract the chroma signal from the current frame to generate the luminance signal.

A method of separating a current frame of a composite video signal into a luminance signal and a chroma signal, the method comprising:

• generating a relative chroma correlation value using a plurality of lines of the current frame;
• generating a weighted sum of inter-line pixel differences of the current frame using the relative chroma correlation value;
• generating a frame difference signal by subtracting a previous frame of the composite video signal from the current frame;
• generating a detected motion signal corresponding to motion detected in the current frame;
• combining the weighted sum of inter-line pixel differences, the frame difference signal, and the detected motion signal to generate the chroma signal;
• and
• subtracting the chroma signal from the current frame to generate the luminance signal.

A system, comprising:

• a composite video source;
• a luminance output;
• a chroma output;
• and
• a luminance and chroma separation circuit adapted to separate a current frame of a signal received from the composite video source into a luminance signal at the luminance output and a chroma signal at the chroma output, the luminance and chroma separation circuit comprising:
• an inter-line correlator adapted to generate a relative chroma correlation value using a plurality of lines of the current frame;
• a line comb adapted to generate a weighted sum of inter-line pixel differences of the current frame using the relative chroma correlation value;
• a frame comb adapted to subtract a previous frame of the composite video signal from the current frame;
• a motion detector adapted to detect motion in the current frame and generate a corresponding detected motion signal;
• a mixer circuit adapted to combine the weighted sum of inter-line pixel differences, an output of the frame comb, and the detected motion signal to generate the chroma signal;
• and
• a subtractor adapted to subtract the chroma signal from the current frame to generate the luminance signal.